Mastitis continued

Question 1

Streptococcus Agalactiae:
type of pathogen
Blood agar

Answer 1

A contagious mastitis pathogen
Gram positive cocci
non haemolytic
Forms very small pin prick colonies on blood agar

Question 2

What type of mastitis does streptococcus agalactiae form?

Answer 2

mastitis graded at 1 and 2
Usuallt sub clinical = high Scc
Not associated with persistent infection

Question 3

How does streptococcus agalactiae appear in the herd and how controlled?

Answer 3

• Failure of parlour hygeine OR introduced by bought in animal
• Control = good hygiene
  Reduce existing infection - treat cases, cull chronic, dry cow therapy and prevent spread within herd:
  Milking parlour
  Wear Gloves
  No common udder cloths/ wipes
  Early detection and treatment
  Post milking teat disinfection
  Milking order
  Maintain milking machine correctly (liners and vacuum)

Question 4

What drug used to treat streptococcus agalactiae

Answer 4

Responds well to antibiotics (penicillin)

Question 5

Streptococcus dysgalactiae
about
What shoudl you immediately think?

Answer 5

Gram positive coccus
Small pin point colonies on Edwards Medium Partial Haemolysis Green Zone
Alpha haemolysis

Udder adn teats are being damaged in some way to cause this

Question 6

Streptococcus dysgalactiae source of infection

Answer 6

Udder, teat skin particularly when skin damaged, tonsils and so cows and heifers licking each others teats important

Question 7

Streptococcus dysgalactiae What sort of infection does it cause?

Answer 7

Can cause persistent infections

Question 8

If Streptococcus dysgalactiae is causing problems in herd what should you do?

Answer 8

particularly check teat condition as proliferates when damaged and look for milking machine pulsator or vacuum problems, check use of emollients in teat dips

Responds well to antibiotics (penicillin)

Question 9

What is mycoplasma?

Answer 9

genus of bacteria that lack a cell wall around their cell membranes.[1] This characteristic makes them naturally resistant to antibiotics that target cell wall synthesis (like the beta-lactam antibiotics = penicillin).

Mycoplasmas are totally dependent on the animals they infect to provide the nutrients they require

Spread by aerosol

Question 10

Types of mycoplasma we see in dairy?

Answer 10

M. bovis and M. californicum

Question 11

What does mycoplasma bovis also cause, other than mastitis

Answer 11

infertility, metritis, otitis media in calves = head tilt, arthritis, keratoconjunctivitis, pneumonia in calves and adults. AGGRESSIVE mastitis where no cure

Interestingly, Often produce marked milk drop and swollen quarter although the cow is not systemically ill

Question 12

Where do cows mainly catch M bovis from?

Answer 12

Highly contagious in parlour , aerosol spread and haematogenous (originated and carried in blood)

Question 13

What pathogenesis to the udder do mycoplasma species cause and why?

Answer 13

Lipoprotein on outer surface  stimulates host immunity  alveolar epithelium degenerates  massive leucocyte outpouring  abscesses, alveolar hypertrophy, fibroplasias around ducts PUS
 destroyed quarter

Question 14

Can you ever be sure mycoplasma isn’t the cause of disease

Answer 14

No as can be sub clinical = reduced tield, high SCC, could alwasy be mycoplasmas

Can be shed for moths and even life!

Question 15

Is mycoplasam easy to culture? and treat?

Answer 15

Difficult to culture; special medium; special request

In vitro sensitivity to several antibiotics , but success very poor = cull

Question 16

Can we feed mastitis milk to calves?

Answer 16

Do not feed milk to calves as could cause disease in calves e.gg mycoplasma causes pneumonia/otitis

Question 17

Control of mycoplasma

Answer 17

affected cows often culled
milking order (affected cows milked last)
Disinfect cluster thoroughly etc. to stop spread;

hygeine like spoken about before

Question 18

What is Coagulase NEgative Staphylococci?

Answer 18

a minor pathogen that is only a problem in those herds that have good control of other pathogens.

Heifers are infected before claving. Causes mild disease including high SCC.

Spontaneous cure common

Treat with antibiotics; usually respond well to penicillin

Often regarded as the cause IF no other pathogens found

Repeat sampling or pure culture or number cases in herd may confirm importance

Question 19

E coli
What type of pathogen?
Source?
What does it form on blood agar?

Answer 19

an environmental pathogen

source: bovine faeces however some evidence there may be udder adapted strains

Blood agar forms creamy white colonies
Haemolytic and non haemolytic
Gram negative rods

Question 20

When is E Coli picked up?

When is it mostly commonly apparent disease?

Answer 20

and picked up any time in calving cycle- whole yr

Often picked up during dry period and induced when she goes from dry cow into environment where calves (peri-periparturient 3 weeks before and after))= most commonly where we see it as a systemic problem

Manifests as high SCC and clinical disease

Question 21

What is a risk factor to ecoli?

Answer 21

Housed = risk factor
Build up of infection over housing period

wet, dirty, poorly ventilated conditions particularly bedding, cubicles, straw yards and calving boxes ,wet muddy fields

Question 22

E coli pathogenesis

Answer 22

Contamination of teat end is followed by invasion of teat canal
Proliferates rapidly producing LPS endotoxin damages vascular and secretory tissue
Clinical outcome of the infection will depend on the quantity and speed of neutrophil influx:
Inadequate or too slow  cow will develop endotoxaemia  often fatal

not really a grumbling thing but acute bang

Question 23

Clinical signs of E coli mastitis

Answer 23

All grades of clinical disease.
Grade 1
clots in milk (self cure)
Grade 2A
clots in milk, hard hot painful quarter
Grade 3 - COMMON
Very sick cow, endotoxaemic shock (usually post calving peri-parturient immunosuppression) udder variable can be cold or hot, hard or soft,
Milk varies from clots to blood
Important differential for downer cow post calving

Not commonly associated with subclinical mastitis and raised cell counts
< 15% become chronically infected

Question 24

How to control E coli mastitis infections

in parlour

Answer 24

Pre-milking teat preparation - Remove the muck! pre dip

Loafing times after milking are contentious - half an hr after milking for teat to close but if main issue lameness then want to lie does asap

Appropriate dry cow therapy - sealent at start of dry cow period to stop infection getting in during dry period

Vaccine - Startvac- not eliminate disease, just reduce severity of clincial